Inhibitory effect of dexamethasone palmitate-low density lipoprotein complex on low density lipoprotein-induced macrophage foam cell formation

We used low density lipoprotein (LDL) as a carrier of site-specific deliver y of drugs to atherosclerotic lesions, prepared a dexamethasone palmitate ( DP)-LDL complex, and examined the effect of the DP-LDL complex on foam cell formation of macrophages in vitro. LDL was isolated from human plasma and the DP-LDL complex was prepared by incubation in the presence of Celite 545 . The complex contained about 50 mol of DP in 1 mol of LDL. When macrophage s were incubated with LDL for 48 h, cholesterol eater was accumulated in th e macrophages, indicating foam cell formation. This accumulation of cholest erol ester was significantly inhibited by incubation with the DP-LDL comple x. The potency of the DP-LDL complex was similar to that of dexamethasone a lone. The DP-LDL complex also significantly attenuated the accumulation of cholesterol ester induced by incubation with LDL prior to the incubation wi th the DP-LDL complex. These findings indicated that the DP-LDL complex sho wed similar characteristics to LDL, and the DP-LDL complex inhibited the fo am cell formation of macrophages in in vitro experiments. This DP-LDL compl ex has a possibility as a drug-carrier complex for use in atherosclerosis.